Memory is a fragile thing. In “Marjorie Prime,” a finalist for the 2015 Pulitzer Prize for drama, playwright Jordan Harrison hits a nerve exploring human identity and the importance of remembering.

Now at Olney Theatre Center, the deftly drawn 80-minute drama rockets its audience to the year 2050. While residential interiors and street clothes look similar to today, at-home technology has advanced markedly. One such advance is “Primes,” which are holograms of deceased loved ones programmed with facts and anecdotes used to help those suffering from dementia to remember their past. It’s an intriguing concept and an interesting way for a playwright to tell a story.

At 85, Marjorie (Kathleen Butler) suffers from dementia and lives with her tightly wound, resentful daughter Tess (Julie-Ann Elliott) and Tess’s far easier going and compassionate husband Jon (Michael Willis). Marjorie spends much of her day reclined on a Lazy Boy chatting with Walter (Michael Glenn), a hologram of her late husband as remembered in his early middle years — vibrant and able. Walter feeds memories and together he and Marjorie amble down a cloudy memory lane. They discuss the night he proposed (it was after seeing “My Best Friend’s Wedding”), but because Marjorie can’t remember, she suggests a different far more romantic memory involving “Casablanca.” Her chatbox companion happily agrees. Similarly, rather than recall their family’s greatest tragedy, they focus on pet dogs and visits to the beach.

The quietly intense action takes place in the living room of Tess and Jon’s house, a modern tasteful mostly glass structure which looks out on a forest of trees, a pleasing design by Misha Kachman. Ivania Stack’s costumes are seemingly contemporary casual, nothing futuristic or distracting about them. Yet the overall design suggests something less cluttered than today.

Written elegantly and sparingly by Brooklyn-based Harrison, who’s gay, “Marjorie Prime” is particularly poignant to aging theatergoers and those who’ve been caretakers for someone with dementia. He conveys the play’s themes of loss and painful past with insight and sensitivity. Harrison first gained attention with his dramatic comedy “Maple and Vine,” a well-received work about a stressed out couple who ditch their cell phones to join a community of 1950s reenactors. He currently writes for the Netflix series “Orange is the New Black,” and a screen version of “Marjorie Prime” starring John Hamm is in works.

Smartly staged by Olney’s out artistic director Jason Loewith, the production boasts an able four-person cast. Butler, who originated parts in three plays by the great gay playwright Edward Albee including B in “Three Tall Women,” gives an affecting portrayal of the declining Marjorie, uncannily capturing the frustrations encountered in early dementia. Heartbreakingly, she apologizes to her daughter for wetting her pants. She conveys the confusion along with remnants of a charming and complex personality. Her performance is the production’s greatest strength.

As “Marjorie Prime” unfolds, Primes become an increasing presence in the characters’ lives. No longer are they employed to simply feed memories to those who can’t remember. Now, they take on different tasks like helping adult children work out unfinished emotional business with dead parents, assisting in grieving and relieving loneliness. The Primes are portrayed as perkier, more patient but vastly less interesting versions of the dead characters’ authentic selves. And while marketed as a comfort and quality of life advancement, they aren’t a substitute for living.